Method with_buffer

crates/stdlib/src/pystruct.rs:165–190

(
            vm: &VirtualMachine,
            format_spec: FormatSpec,
            buffer: ArgBytesLike,
        )

    impl UnpackIterator {
        fn with_buffer(
            vm: &VirtualMachine,
            format_spec: FormatSpec,
            buffer: ArgBytesLike,
        ) -> PyResult<Self> {
            if format_spec.size == 0 {
                Err(new_struct_error(
                    vm,
                    "cannot iteratively unpack with a struct of length 0".to_owned(),
                ))
            } else if !buffer.len().is_multiple_of(format_spec.size) {
                Err(new_struct_error(
                    vm,
                    format!(
                        "iterative unpacking requires a buffer of a multiple of {} bytes",
                        format_spec.size
                    ),
                ))
            } else {
                Ok(Self {
                    format_spec,
                    buffer,
                    offset: AtomicCell::new(0),
                })
            }
        }
    }

    #[pyclass(with(IterNext, Iterable), flags(DISALLOW_INSTANTIATION))]